Because of increasing environmental concerns, the disposal and recycling of waste products has created a demand for more efficient ways of treating wastes for conversion into recycled products that have some commercial value. Therefore, composting is being used with increased frequency to convert waste of all types to valuable soil conditioners. Also, soil that has been contaminated by toxic substances must be removed, cleaned of the toxic material and replaced free of the contaminants. Machines are known and available for the bioremediation of soil and for windrowing disposed waste material into rows or stacks so as to allow the naturally occurring bacterial action to biologically digest the organic materials and convert the waste into a useful product. Since these are aerobic processes, the composted material or soil must be processed in order to introduce and trap oxygen in the material to provide for the proper bioremediation. The composted material or soil must be regularly and thoroughly mixed and aerated to allow the natural biological process to work. This bioremediation process will remove the toxic substances from the soil so that the soil can be replaced free of the contaminants. The process will also convert otherwise waste material into a stable and relatively odorless material which can be used as a soil conditioner.
A variety of machines are known and available for aerating and mixing soil or compost material that is either stored in stacks or windrows. Examples of such machines are shown in U.S. Pat. No. 4,932,196 entitled "Compost Windrow Turner" and U.S. Pat. No. 4,976,095 also entitled "Compost Windrow Turner". Machines shown in these two patents are excellent machines for processing contaminated soil or waste material stored in windrows by elevating and completely agitating and inverting the material and returning it to windrows. Other known machines utilize drums or high speed flails or knives that thrash through the stored material to pulverize it. Generally, the typical machine is designed to aerate either windrowed material or stacked material, but not both. Processors of contaminated soil or waste material will commonly use a windrowing machine or a stacking machine, but not both, because of the expense involved. There are situations, however, where a single user may wish to windrow some of the soil or waste material and stack other of the material. In such instances, there is a need for a single machine that can both aerate material in a windrow configuration or aerate material that is in a stacked configuration. It is also highly desirable that such a machine have the capability of loading the material into a truck or other carrier for transport to another site. Also, machines of this type must frequently be moved from one site to another, and it is desirable that such machines be compact for ease of transport with a minimum amount of loading and set-up time.